Abstract
Purpose: :
The efficacy of corneal collagen cross-linking with riboflavin for halting progession of keratoconus was investigated in a randomized, interindividual, multicenter clinical trial.
Methods: :
A total of 29 patients with progressive keratoconus were randomized in the centers Freiburg, Munich and Würzburg. Mean age at inclusion was 28 (range: 17 to 53) years. The worse eye was, according to the randomization protocol either treated with collagen cross-linking (established protocol: corneal epithelial removal, 0.1% riboflavin, UVA 370 nm at 3 mW/cm2 for 30 minutes) or sham procedure (fluorescein drops, radiation with visible light, no epithelial removal). The longitudinal change in corneal refraction (maximum simulated K-readings) was calculated by means of linear regression for each patient. These data were analyzed according to the intention-to-treat principle and the Kruskal-Wallis test was used to compare keratoconus progession between both groups.
Results: :
15 patients had been randomized to the treatment, and 14 to the control group. The mean follow-up was 1.7 (range 0.5 to 3) years. The corneal refractive power decreased in the treatment group on average (+/-standard deviation) by -0,39 +/- 0,68 diopters/year, whereas in the control-group there was an increase by 0,18 +/- 0,17 diopters/year. The results were not statistically significant (p=0.06).
Conclusions: :
The results of the 29 patients show a tendency that corneal collagen crosslinking can reduce the progression speed in keratoconus. However, the results were not statistically significant. One possible explanation is the lack of statistical power due to a small number of patients included in our trial. Further analysis of the data with longer follow-up might help to decide which patients will benefit most from this promising treatment.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00626716
Keywords: keratoconus • cornea: clinical science